N = int(input())
O = input()
ridx = [i for i, s in enumerate(O) if s == 'R']
n = len([i for i in ridx if i >= len(ridx)])
print(n) N = int(input()) N int(input()) int input() input O = input() O input() input i for i, s in enumerate(O) if s == 'R' for i, s in enumerate(O) if s == 'R' i s enumerate(O) enumerate O s == 'R' s 'R' if s == 'R' i ridx = [i for i, s in enumerate(O) if s == 'R'] ridx [i for i, s in enumerate(O) if s == 'R'] i for i in ridx if i >= len(ridx) for i in ridx if i >= len(ridx) i ridx i >= len(ridx) i len(ridx) len ridx if i >= len(ridx) i n = len([i for i in ridx if i >= len(ridx)]) n len([i for i in ridx if i >= len(ridx)]) len [i for i in ridx if i >= len(ridx)] print(n) print n O = input() input() O ridx = [i for i, s in enumerate(O) if s == 'R'] [i for i, s in enumerate(O) if s == 'R'] ridx N = int(input()) int(input()) N n = len([i for i in ridx if i >= len(ridx)]) len([i for i in ridx if i >= len(ridx)]) n
N = int(input())
O = input()
ridx = [i for i, s in enumerate(O) if s == 'R']
n = len([i for i in ridx if i >= len(ridx)])
print(n)